Lincoln wasn’t an abolitionist.
Lincoln did believe that slavery was morally wrong, but there was one big problem: It was sanctioned by the highest law in the land, the Constitution. The nation’s founding fathers, who also struggled with how to address slavery, did not explicitly write the word “slavery” in the Constitution, but they did include key clauses protecting the institution, including a fugitive slave clause and the three-fifths clause, which allowed Southern states to count slaves for the purposes of representation in the federal government. In a three-hour speech in Peoria, Illinois, in the fall of 1854, Lincoln presented more clearly than ever his moral, legal and economic opposition to slavery—and then admitted he didn’t know exactly what should be done about it within the current political system.
Abraham Lincoln was an abolitionist because he, paraphrased, "saw the dangers of whites and blacks living together." He maintained that, in addition to abolishing slavery, he sought to keep current non-slave states slave-free so that they would be black-free, and before he was assassinated he had started work on a plan to purchase a fair amount of land in Africa or South America to deport all former slaves there.
I think diana5380 also meant to put "No," but for some reason put "Yes." Anyway, he was initially not an abolitionist, and he simply wanted to limit slavery to where it already was. Eventually, however, his intentions changed to where he wanted all slaves to be free in the Emancipation Proclamation.